Wheeled vehicles have been in use for centuries, and wheel construction has evolved as materials, manufacturing methods, and performance needs have evolved. Pneumatic (air filled) tires have been the norm for most vehicles in the United States for most of the past century.
It is estimated that at highway speeds, about seven percent of the energy content in a car's fuel is expended simply in overcoming rolling resistance. Given that up to 69 percent of the energy content is lost in a car's engine during highway driving, about 22 percent of the useful mechanical energy produced by the car's engine may be expended in overcoming rolling resistance. Much of that rolling resistance is due to energy expended in deformation of the car's tires. Because the tires are viscoelastic, and not perfectly elastic, not all of the energy required to deform the tire is returned when the deformed part of the tire regains its shape. One portion of the tire that deforms is the sidewall. There is accordingly a need to reduce energy dissipated in tire sidewall deformation.
Pneumatic tires have the further disadvantage that they can be punctured and deflated by road hazards and the like. With most pneumatic tires, a tire puncture necessitates an immediate, inconvenient and costly repair.